Also known as: del(20q) FISH« Back to test list
Chromosomal abnormalities resulting in deletion of part of the long arm of chromosome 20 (20q) can occur in myeloid neoplasms, including acute myeloid leukaemia (AML) and myelodysplastic syndrome (MDS). These abnormalities can have diagnostic and prognostic implications.
In patients with AML, deletion of 20q is associated with relatively poor prognosis, often occurring as part of a complex karyotype.
In patients with MDS, deletion of 20q (as the sole cytogenetic abnormality) is associated with a favourable prognosis.
This is an assay for non-heritable mutations. It does not raise issues of ethics or consent that are different from most other investigations ordered in the routine care of a patient.
Fluorescent in situ hybridisation (FISH) analysis, using probes within the region of 20q commonly deleted in AML/MDS.
This test is usually requested by a haematologist or oncologist.
0.5 mL bone marrow in transport media (or 10 mL blood in lithium heparin if blasts>10%).
To help ensure the quality of the test, a genetic test should be done with a dedicated sample whenever possible i.e. a sample collected specifically for that test rather than a sample that is used for multiple tests.
We also recommend that the patient or another adult check the labelling of request forms and sample tubes.